David W wrote:.... The battery is by far the weakest link here.... [So] give some details on it, like its age and country of origin....

The age of this battery is no longer an issue, but its apparent country of origin, China, is a big issue. (The words Made in China should be on the lower right portion of the battery's labeling.)

Baldeagle wrote:The battery was the same one on the bike when the old rectifier was fried.It was advertised as "fully charged and ready for use", but I checked the voltage before fitting and it was 12.6 v.At the moment the battery is holding its charge at 12.6 volts ...

12.6 volts was too low for a new, fully charged battery of this type; it was not fully charged when installed. And after you have effectively recharged it by running your engine, the 12.6 value seems even more so too low. What is its current voltage after the engine has stopped and the battery has just sat for about two hours or more, but before the ignition switch is turned on again?

David W wrote:... Of course, you [Bill] did recheck the two intermittent connections which you have already fixed once....

Baldeagle wrote:... I have come to the conclusion that the alternator itself is faulty and putting out too many volts ....

These alternators sometimes reportedly fail, but I think the reported symptom has always been too few volts, not too many. To support that statement, I will now quote a Kawasaki 2008 service manual for the relatively new 1400GTR/Concours because it is the one manual that discusses alternator output:"There are three types of alternator failures: short, open (wire burned out), or loss in rotor magnetism. A short or open ... will result in either a low output, or no output at all. A loss in rotor magnetism ... will result in low output."

Baldeagle wrote:... Just waiting for all the parts I need to arrive and, hopefully, get started next week ....

I think the main part you need to obtain is a premium replacement battery, properly initialized, fully charged and then installed. You can still run the engine at this point, right? Do that with the new battery before tearing into rusty bolts. (The proper initialization is more important than the full charge in your case. The worst that can happen is that you improve your Pan's battery; that is usually a good investment for this bike.)Here is the only reference I know of for high running voltage:

David W wrote:... Again in the Honda [Pan service manual], page 17-1, it says ""Battery overcharge often results from problems in the battery itself, which may appear to be an overcharge symptom. If one of the battery cells is shorted and battery voltage does not increase, the regulator/rectifier supplies excess voltage to the battery." (I estimate Bill should be shopping for a premium battery.)

Baldeagle wrote:... a fully charged battery (13.4 volts), was used.

I was wrong thinking lack of a full charge was the problem in your case, but the 13.4 volt value looks like that of a battery whose voltage has not stabilized yet. Let it stabilize, and measure again, please.Bill might want to also look at the nearby thread on battery basics for the "gel" case, as well as the AGM thread, too.All, please help Bill find a premium battery from his local dealer.

'Tis not its looks, but how it cooks. And I've found that most liter size Pans, when warmed up, cook well.

Baldeagle wrote:... I have come to the conclusion that the alternator itself is faulty .... ... Regards, Bill

None of the service manuals I've seen suggest that. If it is at fault, I think it must be the rotor part. Specifically, the resistance of the coil in the rotor may be abnormally low. The following is my chain of thought on that:The VRR has a rather fixed-voltage power source available to it. If said rotor resistance is too low, when the VRR sends electric current to the rotor, it sends too much. That causes too much "magnetism" in the spinning rotor, which causes the alternator output to be too high.

'Tis not its looks, but how it cooks. And I've found that most liter size Pans, when warmed up, cook well.

mbrST1100 wrote:... <sigh!>...that thing has not rotor-coils... its a brush-less...

A coil is not a brush. I think our earlier rotor contains one coil.

Moving forward on the Pan from the black, two-pin connector towards the alternator, the black wire connects to one end of the rotor coil; the white wire connects to the other end of it. So one can measure the rotor coil resistance by measuring it remotely at the black, two-pin connector. (I think 2.0 to 2.5 "ohms" is a typical range of values of coil resistance on my ST1100.)

Bill might first practice by measuring the rotor coil resistance on the new alternator that he has arriving.If Bill's present (or older) rotor resistance on the Pan is found to be down under say, about 1.0 ohm, that may be the cause of the high running voltage even though the manuals do not say so; they just say the resistance should be in the range from 0.0 to 4.0 ohms.

The advantage of going that route is that Bill finds something amiss with his alternator, something that might cause high output, before replacing the alternator.

David W wrote:[... Specifically, the resistance of the coil in the rotor may be abnormally low. The following is my chain of thought on that: The VRR has a rather fixed-voltage power source available to it. [At least its black wire is at a regulated voltage.] If said rotor resistance is too low, when the VRR sends electric current to the rotor, it sends too much [current]. That [excess current] causes too much "magnetism" in the spinning rotor, which causes the alternator output to be too high.

The purpose of the rotor coil is to form an "electromagnet". If there is no current through the rotor coil, there will be no alternator output at all, regardless of how high the engine rpm is, because there is no magnetism generated by the coil.

'Tis not its looks, but how it cooks. And I've found that most liter size Pans, when warmed up, cook well.

Forest 1100 wrote:... the 28 amp alternator does NOT have a coil in the rotor, just big permanent magnets. Martin tried to tell you this twice, I believe.

Martin said no brushes, I think. He did not mention coils as such.

Martin and Forest will please cite their reference(s) saying our rotor has no coil.

(If it has no coil, why do the manuals tell us to measure the resistance there, using the black and white wires? What is being measured? And how is the output of our alternator being controlled by the voltage regulator?)

'Tis not its looks, but how it cooks. And I've found that most liter size Pans, when warmed up, cook well.

I amended my previous post slightly, after having a closer look at my alternator stator on the bench and at the rotor, still in the engine.

As I said the rotor is just a big chunk of ferrous metal. The black/white wires do lead to a coil, but it is contained within the stator housing, not in the rotor. It is a separate coil from the three coils that create our power source. That coil fits into the centre of the rotor and, when charged, creates a magnetic field in the rotor metal, which, I am thinking, magnifies the field cutting through the three current producing coils. All coils/wiring are contained within the stator housing. No wires go to the rotor.

The "induction?" coil is regulated by the VRR to increase or decrease the output of the other three coils.

David W wrote:... Martin and Forest will please cite their reference(s) saying our rotor has no coil....

Martin has provided pages 17-1 through 17-6 from the Honda manual, the section on the Charging System/Alternator.Page 17-2 of it shows four coils but does not label them except to say that the wires leading to one of them are white and black.Page 17-3 mentions both "charging and field coils" in the alternator.Page 17-5 mentions the white and black wires again, in reference to checking the "Field coil line".Page 17-6 gives the resistance range as 0.0 to 0.4 ohms and does indicate that that component resides in the stator.

So what I have been calling the rotor's coil should be called the field coil. Its purpose is to generate a magnetic field. Maybe it does not spin when the rotor spins; maybe the iron spinning around it is enough. In any case, I think a spinning magnetic field generates the alternator output in the three other stator coils which are fixed; they do not rotate, hence the terms stator (motionless) and rotor (rotating).

Forest 1100 wrote:... in the rotor, it's just a large piece of ferrous metal....

Forest 1100 wrote:... As I said the rotor is just a big chunk of ferrous metal. The black/white wires do lead to a coil, but it is contained within the stator housing, not in the rotor. It is a separate coil from the three coils that create our power source. That coil fits into the centre of the rotor and, when charged, creates a magnetic field in the rotor metal, which, I am thinking, magnifies the field cutting through the three current producing coils.... The "induction?" coil is regulated by the VRR to increase or decrease the output of the other three coils. That's the best I can explain it.

Apparently the iron in the rotor becomes a spinning magnet because the nearby field coil is itself a magnet when current flows through it. Some may call the field coil the induction coil, but we maybe should prefer to use the term Honda uses. The VRR regulates the field coil in order to regulate the output of the other three coils. That's the best I can explain it, too.------------------------------------------------------------------------------------------------------------------------------------The expected resistance in the field coil is around 2.4 ohms, just going from memory.

'Tis not its looks, but how it cooks. And I've found that most liter size Pans, when warmed up, cook well.

rotor... phew, who would have guessed: no windings, nor commutators on that thing now... And since its not that I've done diagnosis and replacements on the 26A systems of my very own bikes, all I seclude on such matter is pure Humbug of course...